Vertical-type non-volatile memory devices and methods of manufacturing the same

ABSTRACT

In a semiconductor device, and a method of manufacturing thereof, the device includes a substrate of single-crystal semiconductor material extending in a horizontal direction and a plurality of interlayer dielectric layers on the substrate. A plurality of gate patterns are provided, each gate pattern being between a neighboring lower interlayer dielectric layer and a neighboring upper interlayer dielectric layer. A vertical channel of single-crystal semiconductor material extends in a vertical direction through the plurality of interlayer dielectric layers and the plurality of gate patterns, a gate insulating layer being between each gate pattern and the vertical channel that insulates the gate pattern from the vertical channel.

RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 12/686,065, which is a continuation application of U.S. applicationSer. No. 12/290,742, filed on Nov. 3, 2008, which relies for priorityupon Korean Patent Application No. 10-2007-0113535, filed on Nov. 8,2007, the contents of each being incorporated herein by reference intheir entirety.

BACKGROUND OF THE INVENTION

With the continued emphasis on highly integrated electronic devices,there is an ongoing need for semiconductor memory devices that operateat higher speeds and lower power and have increased device density. Toaccomplish this, devices with aggressive scaling and multiple-layereddevices with transistor cells arranged in horizontal and vertical arrayshave been under development.

In one approach, planar memory cells, for example NAND memory cells, areformed in a conventional horizontal array. Multiple horizontal arraysare then stacked in a vertical direction. Limitations associated withthis approach include poor reliability in the resulting device, sincecritical lithography steps are required for each layer in achieving theminimum feature size. In addition, in this configuration, the size ofthe driver transistors for driving the control gates is a function ofthe number of layers; therefore, the driver transistors are scaled as amultiple of the number of layers. This can lead to integration issuesand heat removal concerns.

In another approach, multiple-layered memory devices with verticallyoriented channels have been under development. In one configuration, aplurality of gate layers are formed on a substrate, and a verticalchannel penetrates the plurality of gate layers. In each verticalchannel, a lower gate layer is configured to operate as a lower selectgate, a plurality of middle gate layers are configured to operate ascontrol gates, and an upper gate layer is configured to operate as anupper select gate. Upper select gates neighboring each other in a firsthorizontal direction are connected to operate as row selection lines forthe device. Vertical channels neighboring each other are connected in asecond horizontal direction to operate as bit lines for the device.

Others attempting the vertically oriented channel approach have met withlimited success. In one configuration, vertical edge surfaces of thelower and upper select gates are isolated from the vertical channelusing a conventional oxide layer, while vertical edge surfaces of thecontrol gates of the middle gate layers are isolated from the verticalchannel using an ONO-type charge trapping layer, in an attempt to formfloating-gate type non-volatile memory devices. However, a floating gateis difficult to achieve under this approach.

In addition, others have attempted the vertically oriented channelapproach using a poly-silicon vertical channel region. Grain boundariesin a poly-silicon vertical channel lead are associated with crystallinedefects, which can increase resistance and form trap sites in theresulting structure. This can lead to increased resistance in theresulting device, which can decrease device speed and increase devicepower consumption.

Also, others attempting the vertically oriented channel approach haveformed the tunnel oxide layer of the ONO charge-trapping layer using aCVD-formed tunnel oxide. Tunnel oxide formed in this manner can quicklydegrade over time, leading to poor device reliability and poor deviceendurance.

SUMMARY OF THE INVENTION

Embodiments of the present invention are directed to vertical-typesemiconductor memory devices and methods of forming the same. Inparticular, in some embodiments, a single-crystal vertical channel isemployed. This reduces the likelihood of crystalline defects, andmitigates the number of trap sites, leading to reduced deviceresistance, and therefore increased speed and decreased powerconsumption. In addition, in some embodiments, the charge trapping layeris formed to surround the control gate in the region of the verticalchannel, leading to simpler and more reliable device formation. Further,in other embodiments, the tunnel oxide positioned between the chargetrapping layer and the vertical channel is formed of a thermal oxidelayer, which is more resistant to degradation over time, leading toimproved device reliability and endurance. This also provides designerswith greater flexibility in achieving desired device characteristics.

In one aspect, a semiconductor device comprises: a substrate ofsingle-crystal semiconductor material extending in a horizontaldirection; a plurality of interlayer dielectric layers on the substrate;a plurality of gate patterns, each gate pattern between a neighboringlower interlayer dielectric layer and a neighboring upper interlayerdielectric layer; and a vertical channel of single-crystal semiconductormaterial extending in a vertical direction through the plurality ofinterlayer dielectric layers and the plurality of gate patterns, a gateinsulating layer between each gate pattern and the vertical channel thatinsulates the gate pattern from the vertical channel.

In one embodiment, the semiconductor device further comprises a chargetrapping layer between each corresponding gate pattern and gateinsulating layer, the charge trapping layer including: a first portionextending in the vertical direction between the gate pattern and thegate insulating layer; a second portion extending in the horizontaldirection between the gate pattern and the neighboring upper interlayerdielectric layer; and a third portion extending in the horizontaldirection between the gate pattern and the neighboring lower interlayerdielectric layer.

In another embodiment, the charge trapping layer comprises a floatinggate comprising a conducting or a semi-conducting material.

In another embodiment, the gate insulating layer comprises a thermaloxide layer.

In another embodiment: an upper-most gate pattern of the plurality ofgate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device; memory celltransistors of a common string of the semiconductor device are coupledtogether in series by the vertical channel; upper portions of verticalchannels arranged in a second horizontal direction of the semiconductordevice are connected to provide bit lines of the semiconductor device;and the semiconductor device comprises a semiconductor memory device.

In another embodiment, the plurality of interlayer dielectric layerseach comprise a multiple-layered structure comprising a lower insulatinglayer, an intermediate insulating layer and an upper insulating layer,the lower and upper insulating layers comprising a material that hasetch selectivity relative to the intermediate insulating layer.

In another aspect, a semiconductor device comprises: a substrateextending in a horizontal direction; a plurality of interlayerdielectric layers on the substrate; a plurality of gate patterns, eachgate pattern between a neighboring lower interlayer dielectric layer anda neighboring upper interlayer dielectric layer; and a vertical channelextending in a vertical direction through the plurality of interlayerdielectric layers and the plurality of gate patterns, a gate insulatinglayer between each gate pattern and the vertical channel that insulatesthe gate pattern from the vertical channel, and a charge trapping layerbetween each corresponding gate pattern and gate insulating layer, thecharge trapping layer including: a first portion extending in thevertical direction between the gate pattern and the gate insulatinglayer; a second portion extending in the horizontal direction betweenthe gate pattern and the neighboring upper interlayer dielectric layer;and a third portion extending in the horizontal direction between thegate pattern and the neighboring lower interlayer dielectric layer.

In one embodiment, the substrate and the vertical channel comprisesingle-crystal semiconductor material.

In another embodiment, the charge trapping layer comprises a floatinggate comprising a conducting or a semi-conducting material.

In another embodiment, the gate insulating layer comprises a thermaloxide layer.

In another embodiment, an upper-most gate pattern of the plurality ofgate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device; memory celltransistors of a common string of the semiconductor device are coupledtogether in series by the vertical channel; upper portions of verticalchannels arranged in a second horizontal direction of the semiconductordevice are connected to provide bit lines of the semiconductor device;and the semiconductor device comprises a non-volatile semiconductormemory device.

In another embodiment, the plurality of interlayer dielectric layerseach comprise a multiple-layered structure comprising a lower insulatinglayer, an intermediate insulating layer and an upper insulating layer,the lower and upper insulating layers comprising a material that hasetch selectivity relative to the intermediate insulating layer.

In another aspect, a semiconductor device comprises: a substrateextending in a horizontal direction; a plurality of interlayerdielectric layers on the substrate; a plurality of gate patterns, eachgate pattern between a neighboring lower interlayer dielectric layer anda neighboring upper interlayer dielectric layer; and a vertical channelextending in a vertical direction through the plurality of interlayerdielectric layers and the plurality of gate patterns, a gate insulatinglayer comprising a thermal oxide layer between each gate pattern and thevertical channel that insulates the gate pattern from the verticalchannel.

In one embodiment, the substrate and the vertical channel comprisesingle-crystal semiconductor material.

In another embodiment, the device further comprises a charge trappinglayer between each corresponding gate pattern and gate insulating layer,the charge trapping layer including: a first portion extending in thevertical direction between the gate pattern and the gate insulatinglayer; a second portion extending in the horizontal direction betweenthe gate pattern and the neighboring upper interlayer dielectric layer;and a third portion extending in the horizontal direction between thegate pattern and the neighboring lower interlayer dielectric layer.

In another embodiment, the charge trapping layer comprises a floatinggate comprising a conducting or a semi-conducting material.

In another embodiment, an upper-most gate pattern of the plurality ofgate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device; memory celltransistors of a common string of the semiconductor device are coupledtogether in series by the vertical channel; upper portions of verticalchannels arranged in a second horizontal direction of the semiconductordevice are connected to provide bit lines of the semiconductor device;and the semiconductor device comprises a semiconductor memory device.

In another embodiment, the plurality of interlayer dielectric layerseach comprise a multiple-layered structure comprising a lower insulatinglayer, an intermediate insulating layer and an upper insulating layer,the lower and upper insulating layers comprising a material that hasetch selectivity relative to the intermediate insulating layer.

In another aspect, a method of fabricating a semiconductor devicecomprises: providing a substrate of single-crystal semiconductormaterial extending in a horizontal direction; providing a plurality ofinterlayer dielectric layers on the substrate; providing a plurality ofgate patterns, each gate pattern between a neighboring lower interlayerdielectric layer and a neighboring upper interlayer dielectric layer;providing a vertical channel of single-crystal semiconductor materialextending in a vertical direction through the plurality of interlayerdielectric layers and the plurality of gate patterns; and providing agate insulating layer between each gate pattern and the vertical channelthat insulates the gate pattern from the vertical channel.

In one embodiment, the method further comprises providing a chargetrapping layer between each corresponding gate pattern and gateinsulating layer, the charge trapping layer including: a first portionextending in the vertical direction between the gate pattern and thegate insulating layer; a second portion extending in the horizontaldirection between the gate pattern and the neighboring upper interlayerdielectric layer; and a third portion extending in the horizontaldirection between the gate pattern and the neighboring lower interlayerdielectric layer.

In another embodiment, the charge trapping layer comprises a floatinggate comprising a conducting or a semi-conducting material.

In another embodiment, providing the gate insulating layer comprises aproviding a thermal oxide layer.

In another embodiment: an upper-most gate pattern of the plurality ofgate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device, and furthercomprising: coupling memory cell transistors of a common string of thesemiconductor device together in series; and connecting upper portionsof vertical channels arranged in a second horizontal direction of thesemiconductor device to provide bit lines of the semiconductor device,wherein the semiconductor device comprises a semiconductor memorydevice.

In another embodiment, providing each of the plurality of interlayerdielectric layers comprises providing a multiple-layered structurecomprising a lower insulating layer, an intermediate insulating layerand an upper insulating layer, the lower and upper insulating layerscomprising a material that has etch selectivity relative to theintermediate insulating layer.

In another aspect, a method of fabricating a semiconductor devicecomprises: providing a substrate extending in a horizontal direction;providing a plurality of interlayer dielectric layers on the substrate;providing a plurality of gate patterns, each gate pattern between aneighboring lower interlayer dielectric layer and a neighboring upperinterlayer dielectric layer; providing a vertical channel extending in avertical direction through the plurality of interlayer dielectric layersand the plurality of gate patterns; providing a gate insulating layerbetween each gate pattern and the vertical channel that insulates thegate pattern from the vertical channel; and providing a charge trappinglayer between each corresponding gate pattern and gate insulating layer,the charge trapping layer including: a first portion extending in thevertical direction between the gate pattern and the gate insulatinglayer; a second portion extending in the horizontal direction betweenthe gate pattern and the neighboring upper interlayer dielectric layer;and a third portion extending in the horizontal direction between thegate pattern and the neighboring lower interlayer dielectric layer.

In one embodiment, providing the substrate comprises providing asubstrate comprising single-crystal semiconductor material, whereinproviding the vertical channel comprises providing a vertical channelcomprising single-crystal semiconductor material.

In another embodiment, the charge trapping layer comprises a floatinggate comprising a conducting or a semi-conducting material.

In another embodiment, providing the gate insulating layer comprises aproviding a thermal oxide layer.

In another embodiment: an upper-most gate pattern of the plurality ofgate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device, and furthercomprising: coupling memory cell transistors of a common string of thesemiconductor device together in series; and connecting upper portionsof vertical channels arranged in a second horizontal direction of thesemiconductor device to provide bit lines of the semiconductor device,wherein the semiconductor device comprises a non-volatile semiconductormemory device.

In another embodiment, providing each of the plurality of interlayerdielectric layers comprises providing a multiple-layered structurecomprising a lower insulating layer, an intermediate insulating layerand an upper insulating layer, the lower and upper insulating layerscomprising a material that has etch selectivity relative to theintermediate insulating layer.

In another aspect, a method of fabricating a semiconductor devicecomprises: providing a substrate extending in a horizontal direction;providing a plurality of interlayer dielectric layers on the substrate;providing a plurality of gate patterns, each gate pattern between aneighboring lower interlayer dielectric layer and a neighboring upperinterlayer dielectric layer; providing a vertical channel extending in avertical direction through the plurality of interlayer dielectric layersand the plurality of gate patterns; and providing a gate insulatinglayer comprising a thermal oxide layer between each gate pattern and thevertical channel that insulates the gate pattern from the verticalchannel.

In one embodiment, providing the substrate comprises providing asubstrate comprising single-crystal semiconductor material, andproviding the vertical channel comprises providing a vertical channelcomprising single-crystal semiconductor material.

In another embodiment, the method further comprises providing a chargetrapping layer between each corresponding gate pattern and gateinsulating layer, the charge trapping layer including: a first portionextending in the vertical direction between the gate pattern and thegate insulating layer; a second portion extending in the horizontaldirection between the gate pattern and the neighboring upper interlayerdielectric layer; and a third portion extending in the horizontaldirection between the gate pattern and the neighboring lower interlayerdielectric layer.

In another embodiment, the charge trapping layer comprises a floatinggate comprising a conducting or a semi-conducting material.

In another embodiment: an upper-most gate pattern of the plurality ofgate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device, and furthercomprising: coupling memory cell transistors of a common string of thesemiconductor device together in series; and connecting upper portionsof vertical channels arranged in a second horizontal direction of thesemiconductor device to provide bit lines of the semiconductor device,wherein the semiconductor device comprises a semiconductor memorydevice.

In another embodiment, providing each of the plurality of interlayerdielectric layers comprises providing a multiple-layered structurecomprising a lower insulating layer, an intermediate insulating layerand an upper insulating layer, the lower and upper insulating layerscomprising a material that has etch selectivity relative to theintermediate insulating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theembodiments of the invention will be apparent from the more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention. In the drawings:

FIG. 1 is a cross-sectional perspective view of vertical-channel memorydevice, in accordance with an embodiment of the present invention. FIG.2 is a close-up view of a channel region of one of the devices of thevertical-channel memory device, in accordance with an embodiment of thepresent invention.

FIGS. 3A-3P are cross-sectional views of a method of forming avertical-channel memory device, in accordance with an embodiment of thepresent invention.

FIG. 4 is cross-sectional perspective view of vertical-channel memorydevice, in accordance with another embodiment of the present invention.

FIGS. 5A-5L are cross-sectional views of a method of forming avertical-channel memory device, in accordance with another embodiment ofthe present invention.

FIG. 6 is cross-sectional view of a vertical-channel memory device, inaccordance with another embodiment of the present invention,illustrating positioning of the cell region of the device on theperipheral circuit region of the device.

FIGS. 7A-7E are cross-sectional views of a method of forming thevertical-channel memory device of FIG. 6, in accordance with anotherembodiment of the present invention, illustrating the formation of thecell region of the device on the peripheral circuit region of thedevice.

FIG. 8 is cross-sectional view of a vertical-channel memory device, inaccordance with another embodiment of the present invention,illustrating positioning of the cell region of the device on theperipheral circuit region of the device.

FIG. 9 is a cross-sectional view of a method of forming avertical-channel memory device, where the vertical channels are formedof a single-crystal semiconductor material formed using selectiveepitaxial growth (SEG), in accordance with an embodiment of the presentinvention.

FIG. 10 is a block diagram of a nonvolatile memory device in accordancewith exemplary embodiments of the present invention.

FIG. 11 is a block diagram of a system including a semiconductor memorydevice in accordance with exemplary embodiments of the presentinvention.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will now be described more fullyhereinafter with reference to the accompanying drawings, in whichpreferred embodiments of the invention are shown. This invention may,however, be embodied in different forms and should not be construed aslimited to the embodiments set forth herein. Like numbers refer to likeelements throughout the specification.

It will be understood that, although the terms first, second, etc. areused herein to describe various elements, these elements should not belimited by these terms. These terms are used to distinguish one elementfrom another. For example, a first element could be termed a secondelement, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element is referred to as being “on”or “connected” or “coupled” to another element, it can be directly on orconnected or coupled to the other element or intervening elements can bepresent. In contrast, when an element is referred to as being “directlyon” or “directly connected” or “directly coupled” to another element,there are no intervening elements present. Other words used to describethe relationship between elements should be interpreted in a likefashion (e.g., “between” versus “directly between,” “adjacent” versus“directly adjacent,” etc.). When an element is referred to herein asbeing “over” another element, it can be over or under the other element,and either directly coupled to the other element, or interveningelements may be present, or the elements may be spaced apart by a voidor gap.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting of the invention. As usedherein, the singular forms “a,” “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

FIG. 1 is a cross-sectional perspective view of vertical-channel memorydevice, in accordance with an embodiment of the present invention. FIG.2 is a close-up view of a channel region of one of the devices of thevertical-channel memory device, in accordance with an embodiment of thepresent invention.

Referring to FIG. 1, in this example, a substrate 100 of single-crystalsemiconductor material is provided. In various embodiments, thesubstrate can comprise bulk single-crystal material, a single-crystalSOI configuration, or other suitable substrate configuration. Thesubstrate 100 extends in a horizontal direction. An optional padoxidation layer 102 is on the substrate 100. A plurality of interlayerdielectric layers 105 a, 105 b, 105 c, 105 d, . . . are provided on thepad oxidation layer 102. A plurality of gate patterns 132 a, 132 b, 132c, 132 d are provided, each gate pattern being between a neighboringlower interlayer dielectric layer 105 a, 105 b, 105 c, 105 d, . . . anda neighboring upper interlayer dielectric layer 105 a, 105 b, 105 c, 105d, . . . . For example, gate pattern 132 a is between neighboring lowerinterlayer dielectric layer 105 a and neighboring upper interlayerdielectric layer 105 b, gate pattern 132 b is between neighboring lowerinterlayer dielectric layer 105 b and neighboring upper interlayerdielectric layer 105 c, gate pattern 132 c is between neighboring lowerinterlayer dielectric layer 105 c and neighboring upper interlayerdielectric layer 105 d, etc.

A vertical channel 116 of single-crystal semiconductor material extendsin a vertical direction through the plurality of interlayer dielectriclayers 105 a, 105 b, 105 c, 105 d, . . . and the plurality of gatepatterns 132 a, 132 b, 132 c, 132 d, . . . . The vertical channel 116 issurrounded by each of the gate patterns 132 a, 132 b, 132 c, 132 d, . .. . For example, gate pattern 132 a surrounds, or encompasses, theperimeter of the lower-most portion of the walls of the vertical channel116. The same holds true for the other gate patterns 132 b, 132 c, 132d, . . . . A gate insulating layer 124 a, 124 b, 124 c, 124 d, . . . isprovided between each gate pattern 132 a, 132 b, 132 c, 132 d, . . . andthe vertical channel 116. The gate insulating layer insulates the gatepattern 132 a, 132 b, 132 c, 132 d, . . . from the vertical channel 116.In one embodiment, the gate insulating layer 124 a, 124 b, 124 c, 124 d,. . . comprises a thermal oxide layer.

In an example where the vertical-channel memory device comprises anon-volatile memory device, a charge trapping layer 126 is providedbetween each corresponding gate pattern 132 a, 132 b, 132 c, 132 d, . .. and gate insulating layer 124 a, 124 b, 124 c, 124 d, . . . .Referring to FIG. 2, in one embodiment, the charge trapping layerincludes: a first portion 127 a extending in the vertical directionbetween the gate pattern 132 a and the gate insulating layer 124 a; asecond portion 127 b extending in the horizontal direction between thegate pattern 132 a and the neighboring upper interlayer dielectric layer105 b; and a third portion 127 c extending in the horizontal directionbetween the gate pattern 132 a and the neighboring lower interlayerdielectric layer 105 a. A blocking layer 128 formed of insulativematerial is between the charge trapping layer 126 and the gate pattern132 a, 132 b, 132 c, 132 d, . . .

In various embodiments, the charge trapping layer 126 is in the form ofa floating gate comprising a conducting or a semiconducting material.Alternatively, the charge trapping layer 126 can comprise an ONO,nitride, polysilicon, or quantum-dot structures.

In an embodiment, in a semiconductor memory device configured inaccordance with embodiments of the present invention, an upper-most gatepattern, for example gate pattern 132 d, of the plurality of gatepatterns comprises an upper select gate of an upper select transistor;and a lower-most gate pattern, for example gate pattern 132 a, of theplurality of gate patterns comprises a lower select gate of a lowerselect transistor. Remaining gate patterns, for example gate patterns132 b, 132 c, of the plurality of gate patterns between the upper selectgate 132 d and the lower select gate 132 a, comprise control gates ofmemory cell transistors of a common string of the semiconductor device.Control gates of memory cell transistors sharing a same layer of thedevice arranged in a first horizontal direction of the semiconductordevice are connected to provide word lines of the semiconductor device.Memory cell transistors of a common string of the semiconductor deviceare coupled together in series by the vertical channel 116. Upperportions of vertical channels 116 arranged in a second horizontaldirection of the semiconductor device are connected, for example bylines 140 to provide bit lines of the semiconductor device. Althoughthis example illustrates only two memory cell transistors in eachvertical channel for purposes of clear illustration of the embodimentsof the present invention, embodiments of the present invention are notthus limited, and can include as few as one memory cell transistor ineach vertical channel, and as many memory cell transistors in verticalchannel as desired for the application, for example, two, four, eight,sixteen, or thirty-two transistors.

In some embodiments, as will be described below in connection with FIG.4 and FIGS. 5A-5L the plurality of interlayer dielectric layers eachcomprise a multiple-layered structure 205 comprising a lower insulatinglayer 205 a, an intermediate insulating layer 205 b and an upperinsulating layer 205 c, the lower and upper insulating layers 205 a, 205c comprising a material that has etch selectivity relative to theintermediate insulating layer 205 b.

FIGS. 3A-3P are cross-sectional views of a method of forming avertical-channel memory device, in accordance with an embodiment of thepresent invention.

Referring to FIG. 3A, a substrate 100 is prepared. In one embodiment,the substrate 100 comprises a single-crystal semiconductor materialsubstrate that provides a seed layer for later formation of thesingle-crystal vertical channels 116. An optional pad oxide layer 102 isprovided on the upper surface of the substrate 100. Multiple alternatinginterlayer dielectric layers 104 a, 104 b, 104 c, 104 d, 104 e, . . .and sacrificial layers 106 a, 106 b, 106 c, 106 d, 106 e, . . . areformed on the pad oxide layer 102. In one embodiment, the interlayerdielectric layers 104 and the sacrificial layers 106 have etchselectivity with respect to each other. For example, the interlayerdielectric layers 104 can comprise silicon nitride and the sacrificiallayers 106 can comprise silicon oxide. Alternatively, the interlayerdielectric layers 104 can comprise silicon oxide and the sacrificiallayers 106 can comprise silicon nitride. In one embodiment, thesacrificial layers 106 are formed of a material that can readily beremoved by a wet etching process.

Referring to FIG. 3B, first openings 110 are formed through theinterlayer dielectric layers 104, the sacrificial layers 106, and thepad oxide layer 102 in a vertical direction, and spaced apart in ahorizontal direction, as shown. The first openings 110 expose upperportions of the underlying substrate 100.

Referring to FIG. 3C, a first poly-silicon layer 112 or first amorphoussilicon layer 112 is formed in the first openings 110, in contact withthe exposed upper portions of the substrate 100. In one embodiment, thefirst poly-silicon layer 112 or first amorphous silicon layer 112 can beformed by a chemical-vapor deposition (CVD) process; however, othersuitable processes for forming the first poly-silicon layer 112 or firstamorphous silicon layer 112 may be applied. In one embodiment, the firstpoly-silicon layer 112 or first amorphous silicon layer 112 can be dopedwith impurities at this stage, for example, doped with n-typeimpurities.

Referring to FIG. 3D, a heat treatment is applied to the firstpoly-silicon layer 112 or first amorphous silicon layer 112 to convertthe layer to a single-crystal silicon pattern 114, that has the samecrystal orientation as that of the underlying substrate 100. In oneexample embodiment, the heat-treatment can take the form of alaser-induced epitaxial growth (LEG) process to obtain thesingle-crystal silicon pattern 114, as is known in the art.

Referring to FIG. 9, in an alternative embodiment, single-crystalsilicon patterns 114-1 can be grown in the openings 110-1 of FIG. 3Bfrom the upper surface of the substrate 100 using a selective epitaxialgrowth (SEG) process. The SEG process is performed using the exposedsubstrate region 100 as a seed layer. The exposed substrate region 100can comprise a semiconductor material, for example, a single-crystalsemiconductor material.

Referring to FIG. 3E, an optional chemical-mechanical polishing (CMP)process can be performed on the uppermost sacrificial layer 106 e, toexpose the underlying uppermost interlayer dielectric layer 104 e. Anupper portion of the single-crystal silicon patterns 114 can be removedduring this procedure.

Referring to FIG. 3F, a plurality of second openings 120 are formedbetween neighboring single-crystal silicon patterns 114, to thereby forminterlayer dielectric layer patterns 105 a, 105 b, 105 c, 105 d, 105 e,. . . and sacrificial layer patterns 107 a, 107 b, 107 c, 107 d, . . .In one embodiment, the second openings 120 expose the lowermostinterlayer dielectric layer pattern 105 a. This procedure permits accessto a region where the control gates and floating gates of the resultingmemory device will be formed along the resulting vertical channels.

Referring to FIG. 3G, the sacrificial layer patterns 107 a, 107 b, 107c, 107 d, . . . are removed by a wet etching process. In an examplewhere the sacrificial layer patterns 107 a, 107 b, 107 c, 107 d, . . .are formed of silicon nitride, the etchant of the wet etching processcan comprise an HF solution. Resulting concave openings 122 surround thewalls of the single-crystal silicon patterns 114, to expose the walls atall sides thereof. FIG. 3H is a perspective view of the resultingstructure.

Referring to FIG. 31, impurity doping 121 can be performed at theexposed sidewalls of the single-crystal silicon patterns 114. Forexample, injection of p-type impurities can be performed at the exposedsidewalls. A plasma doping (PLAD) process can be used for performing theinjection.

Assuming the bodies of the single-crystal silicon patterns 114 are dopedabove with n-type impurities, as described above in connection with FIG.3C, the formation of p-type doped regions in the single-crystal siliconpatterns 114 at the exposed sidewalls creates p-type channel regions 117a for the resulting vertical channels 116 that are positioned betweenn-type source/drain regions 117 b of the vertical channels 116, as shownin close-up view in FIG. 2. The p-type channel regions 117 a are“self-aligned” in the vertical channels 116 as a result of therespective positions of the interlayer dielectric layer patterns 105 a,105 b, 105 c, 105 d, 105 e. Although the p-type channel regions 117 bare shown in the close-up view of FIG. 2 as extending across the entirebody of the vertical channel, in other embodiments, the p-type channelregions 117 b only extend slightly into the body of the vertical channel116, from its surface.

Referring to FIG. 3J, tunnel oxide layers 124 a, 124 b, 124 c, 124 d, .. . are formed at the exposed sidewalls of the resulting verticalchannels 116. The tunnel oxide layers 124 a, 124 b, 124 c, 124 d, . . .surround the vertical channels, for example, in a case where thevertical channels 116 are circular in cross-section, the tunnel oxidelayers 124 a, 124 b, 124 c, 124 d, . . . are ring-shaped. In oneembodiment, the tunnel oxide layers 124 a, 124 b, 124 c, 124 d, . . .are formed using a thermal oxidation process. A tunnel oxide layerformed using a thermal oxidation process is more resistant todegradation over time, leading to improved device reliability andendurance.

Referring to FIG. 3K, a charge trapping layer 126 is applied to theresulting structure, coating the walls of the concave openings 122,including the interlayer dielectric layer patterns 105 a, 105 b, 105 c,105 d, 105 e, . . . and the tunnel oxide layers 124 a, 124 b, 124 c, 124d, . . . In various embodiments, the charge trapping layer 126 can be afloating-gate structure, for example, comprising a poly-siliconmaterial. In other embodiments, the charge trapping layer 126 cancomprise an ONO (oxide-nitride-oxide) structure, a nitride structure, apolysilicon structure, or quantum-dot structures. A floating-gate chargetrapping layer 126 is possible in the embodiments of the presentinvention, since access is gained behind the tunnel oxide layers 124 a,124 b, 124 c, 124 d, . . . at the concave openings 122.

A blocking insulating layer 128 is formed on the resulting structure,covering the charge trapping layer 126. In one example embodiment, theblocking oxide layer 128 comprises silicon oxide, or other suitablehigh-k oxide layer.

Referring to FIG. 3L, a conductive material is provided to fill thesecond openings 120, including the concave openings 122, resulting inthe formation of conductive patterns 130. In one embodiment, theconductive material comprises tungsten silicide.

Referring to FIG. 3M, the central portions of the conductive patterns130 are etched, forming third openings 134 that expose the surface ofthe lowermost interlayer dielectric layer 105 a, and expose outersidewalls of the interlayer dielectric layer patterns 105 a, 105 b, 105c, 105 d, 105 e, . . . . This separates portions of the conductivepatterns 130 that fill the concave openings 122 into gate patterns 132a, 132 b, 132 c, 132 d, . . . , and separates the charge trapping layerinto individual charge trapping layer patterns. FIG. 3N is a perspectiveview of the resulting structure.

Referring to FIG. 3O, the third openings 134 are filled with aninsulation pattern 136.

Referring to FIG. 3P, conductive bit lines 140 are formed and patternedto connect neighboring vertical channels 116 in a second horizontaldirection of the semiconductor device, as described above in connectionwith FIG. 1.

FIG. 4 is cross-sectional perspective view of vertical-channel memorydevice, in accordance with another embodiment of the present invention.This embodiment is substantially similar in configuration to theembodiment shown and described above in connection with FIGS. 1, 2, and3A-3P. A difference, however, lies in that the interlayer dielectriclayer patterns 202, 205, 207, 209, 211 of the present embodiment areformed of multiple layers, rather than of a single layer.

Referring to FIG. 4, in this embodiment, a substrate 200 ofsingle-crystal semiconductor material is provided. The substrate 200extends in a horizontal direction. A plurality of interlayer dielectriclayer pattern 202, 205, 207, 209, 211, . . . are provided on thesubstrate 200. A plurality of gate pattern 258 a, 258 b, 258 c, 258 d, .. . are provided, each gate pattern being between a neighboring lowerinterlayer dielectric layer patterns 202, 205, 207, 209, 211, . . . anda neighboring upper interlayer dielectric layer patterns 202, 205, 207,209, 211, . . . .

A vertical channel 230 of single-crystal semiconductor material extendsin a vertical direction through the plurality of interlayer dielectriclayer patterns 202, 205, 207, 209, 211, . . . and the plurality of gatepatterns 258 a, 258 b, 258 c, 258 d, . . . . The vertical channel 230 issurrounded by each of the gate patterns 258 a, 258 b, 258 c, 258 d, . .. . A gate insulating layer 238 a, 238 b, 238 c, 238 d, . . . isprovided between each gate pattern 258 a, 258 b, 258 c, 258 d and thevertical channel 230. The gate insulating layers 238 a, 238 b, 238 c,238 d, . . . insulate the corresponding gate pattern 258 a, 258 b, 258c, 258 d, . . . from the vertical channel 230. In one embodiment, asdescribed above, the gate insulating layers 238 a, 238 b, 238 c, 238 d,. . . comprise a thermal oxide layer.

In an example where the vertical-channel memory device comprises anon-volatile memory device, a charge trapping layer 250 is providedbetween each corresponding gate pattern 258 a, 258 b, 258 c, 258 d, . .. and gate insulating layer 238 a, 238 b, 238 c, 238 d, . . . Asdescribed above in connection with the close-up view of FIG. 2, in oneembodiment, the charge trapping layer 250 can include: a first portion127 a extending in the vertical direction between the gate pattern 132 aand the gate insulating layer 124 a; a second portion 127 b extending inthe horizontal direction between the gate pattern 132 a and theneighboring upper interlayer dielectric layer 105 b; and a third portion127 c extending in the horizontal direction between the gate pattern 132a and the neighboring lower interlayer dielectric layer 105 a. Ablocking layer 252 formed of insulative material is between the chargetrapping layer 250 and the gate pattern 258 a, 258 b, 258 c, 258 d, . ..

In various embodiments, the charge trapping layer 250 is in the form ofa floating gate comprising a conducting or a semiconducting material.Alternatively, the charge trapping layer can comprise an ONO, nitride,polysilicon, or quantum-dot structure

In an embodiment, in a semiconductor memory device configured inaccordance with embodiments of the present invention, an upper-most gatepattern, for example gate pattern 258 d, of the plurality of gatepatterns comprises an upper select gate of an upper select transistor;and a lower-most gate pattern, for example gate pattern 258 a, of theplurality of gate patterns comprises a lower select gate of a lowerselect transistor. Remaining gate patterns, for example gate patterns258 b, 258 c, of the plurality of gate patterns between the upper selectgate 258 d and the lower select gate 258 a, comprise control gates ofmemory cell transistors of a common string of the semiconductor device.Control gates of memory cell transistors sharing a same layer of thedevice arranged in a first horizontal direction of the semiconductordevice are connected to provide word lines of the semiconductor device.Memory cell transistors of a common string of the semiconductor deviceare coupled together in series by the vertical channel 230. Upperportions of vertical channels 230 arranged in a second horizontaldirection of the semiconductor device are connected, for example bylines 262 to provide bit lines of the semiconductor device. As describedabove, although this example illustrates only two memory celltransistors in each vertical channel for purposes of clear illustrationof the embodiments of the present invention, embodiments of the presentinvention are not thus limited, and can include as few as one memorycell transistor in each vertical channel, and as many memory celltransistors in vertical channel as desired for the application, forexample, two, four, eight, sixteen, or thirty-two transistors.

FIGS. 5A-5L are cross-sectional views of a method of forming avertical-channel memory device, in accordance with another embodiment ofthe present invention.

Referring to FIG. 5A, a substrate 200 is prepared. In one embodiment,the substrate 200 comprises a single-crystal semiconductor materialsubstrate that provides a seed layer for later formation of thesingle-crystal vertical channels 230. Multiple alternating interlayerdielectric layers 202, 204, 206, 208, 210, . . . and sacrificial layers212, 214, 216, 218, . . . are formed on the substrate 200. In thepresent embodiment, the interlayer dielectric layers 202, 204, 206, 208,210, . . . each comprise a multiple-layered structures. For example, thelowermost interlayer dielectric layer 202 comprises a lower insulatinglayer 202 a comprising silicon oxide and an upper interlayer dielectriclayer comprising silicon nitride. Similarly, the uppermost interlayerdielectric layer 210 comprises a lower insulating layer 202 a comprisingsilicon nitride and an upper interlayer dielectric layer comprisingsilicon oxide. The interlayer dielectric layers between the lowermostinterlayer dielectric layer 202 and the uppermost interlayer dielectriclayer 210, including interlayer dielectric layers 204, 206, 208 eachcomprise a lower insulating layer 204 a, 206 a, 208 a comprising siliconnitride, an intermediate insulating layer 204 b, 206 b, 208 b comprisingsilicon oxide and an upper insulating layer 204 c, 206 c, 208 ccomprising silicon nitride. In this manner, the lower and upperinsulating layers comprise a material that has etch selectivity relativeto the intermediate insulating layer. In this embodiment, thesacrificial layers 212, 214, 216, 218, . . . can comprise a materialthat has etch selectivity relative to both silicon oxide and siliconnitride, for example, polysilicon germanium. In this manner, thesacrificial layers 212, 214, 216, 218, . . . can readily be removed by awet etching process during subsequent fabrication steps.

Referring to FIG. 5B, first openings 220 are formed through theinterlayer dielectric layers 202, 204, 206, 208, 210, . . . and thesacrificial layers 212, 214, 216, 218, . . . in a vertical direction,and spaced apart in a horizontal direction, as shown. The first openings220 expose upper portions of the underlying substrate 100 to provide apatterned resulting structure 224.

Referring to FIG. 5C, silicon oxide spacers 238 are formed on innersidewalls of the first openings 220 of the resulting structure 224. Thespacers 238 operate to promote substantially uniform formation of thesingle-crystal silicon vertical channels using the LEG formation processor to promote substantially uniform growth of the single-crystal siliconvertical channels using the SEG formation process, as described above.The spacers prevent crystalline defect formation in the single-crystalsilicon that might otherwise be introduced at any oxide-nitrideinterface in the resulting structure 224.

Referring to FIG. 5D, a first poly-silicon layer 228 or first amorphoussilicon layer 228 is formed in the first openings 220, in contact withthe exposed upper portions of the substrate 200. In one embodiment, thefirst poly-silicon layer 228 or first amorphous silicon layer 228 can beformed by a chemical-vapor deposition (CVD) process; however, othersuitable processes for forming the first poly-silicon layer 228 or firstamorphous silicon layer 228 may be applied. In one embodiment, the firstpoly-silicon layer 228 or first amorphous silicon layer 228 can be dopedwith impurities at this stage, for example, doped with n-typeimpurities.

Referring to FIG. 5E, a heat treatment is applied to the firstpoly-silicon layer 228 or first amorphous silicon layer 228 to convertthe layer to a single-crystal silicon pattern 230, that has the samecrystal orientation as that of the underlying substrate 200. In oneexample embodiment, the heat-treatment can take the form of alaser-induced epitaxial growth (LEG) process to obtain thesingle-crystal silicon pattern 230, as is known in the art.

In an alternative embodiment, single-crystal silicon patterns 230 can begrown in the openings 220 of FIG. 5C from the upper surface of thesubstrate 200 using a selective epitaxial growth (SEG) process, asdescribed above.

Referring to FIG. 5F, an optional chemical-mechanical polishing (CMP)process can be performed on the upper surface of the resulting structureto remove and planarized an upper portion of the single-crystal siliconpatterns 230. A plurality of second openings 232 are then formed betweenneighboring single-crystal silicon patterns 230, to thereby forminterlayer dielectric layer patterns 205 a, 205 b, 205 c, 205 d, 205 e,. . . and corresponding sacrificial layer patterns. In one embodiment,the second openings 232 expose the lowermost interlayer dielectric layerpattern 202. This procedure permits access to a region where the controlgates and floating gates of the resulting memory device will be formedalong the vertical channels 230. The sacrificial layer patterns 212,214, 216, 218, . . . are then removed by a wet etching process. In anexample where the sacrificial layer patterns 212, 214, 216, 218, . . .are formed of polysilicon germanium, the etchant of the wet etchingprocess can comprise an oxidizer A/HF mixture solution.

Resulting concave openings 234 surround the walls of the single-crystalsilicon patterns 230, to expose the spacers 238 at the sides thereof.Referring to FIG. 5G, exposed portions of the spacers 238 are nextremoved, for example using a wet etching process. In an embodiment wherethe spacers comprise silicon oxide, the etchant of the wet etchingprocess can comprise an HF solution.

At this time, impurity doping can be performed at the exposed sidewallsof the single-crystal silicon patterns 230, as described above inconnection with FIG. 3I. The resulting channel regions are“self-aligned” in the vertical channels 230 as a result of therespective positions of the interlayer dielectric layer patterns 205 a,205 b, 205 c, 205 d, 205 e, . . .

Referring to FIG. 5H, tunnel oxide layers 238 a, 238 b, 238 c, 238 d, .. . are formed at the exposed sidewalls of the resulting verticalchannels 230. The tunnel oxide layers 238 a, 238 b, 238 c, 238 d, . . .surround the vertical channels, for example, in a case where thevertical channels 230 are circular in cross-section, the tunnel oxidelayers 238 a, 238 b, 238 c, 238 d, . . . are ring-shaped. In oneembodiment, the tunnel oxide layers 238 a, 238 b, 238 c, 238 d, . . .are formed using a thermal oxidation process. A tunnel oxide layerformed using a thermal oxidation process is more resistant todegradation over time, leading to improved device reliability andendurance.

Referring to FIG. 5I, a charge trapping layer 250 is applied to theresulting structure, coating the walls of the concave openings 234,including the interlayer dielectric layer patterns 205, 207, 209, 211, .. . and the tunnel oxide layers 238 a, 238 b, 238 c, 238 d, . . .

In various embodiments, the charge trapping layer 250 can be afloating-gate structure, for example, comprising a poly-siliconmaterial. In other embodiments, the charge trapping layer 250 cancomprise an ONO (oxide-nitride-oxide) structure. Other charge trappinglayer 250 structures can also be employed, including nitride,polysilicon, or quantum-dot structures, or other applicable chargetrapping structures. A floating-gate charge trapping layer 250 ispossible in the embodiments of the present invention, since access isgained behind the tunnel oxide layers 238 a, 238 b, 238 c, 238 d, . . .at the concave openings 234. A blocking insulating layer 252 is formedon the resulting structure, covering the charge trapping layer 250. Inone example embodiment, the blocking oxide layer 252 comprises siliconoxide, or other suitable high-k oxide layer. A conductive material isprovided to fill the second openings 232, including the concave openings234, resulting in the formation of conductive patterns 254. In oneembodiment, the conductive material comprises tungsten silicide.

Referring to FIG. 5J, the central portions of the conductive patterns254 are etched, forming third openings 256 that expose the surface ofthe lowermost interlayer dielectric layer 202, and expose outersidewalls of the interlayer dielectric layer patterns 205, 207, 209,211, . . . . This separates portions of the conductive patterns 254 thatfill the concave openings 234 into gate patterns 258 a, 258 b, 258 c,258 d, . . . , and separates the charge trapping layer into individualcharge trapping layer patterns 250.

Referring to FIG. 5K, the third openings 256 are filled with aninsulation pattern 260.

Referring to FIG. 5L, conductive bit lines 262 are formed and patternedto connect neighboring vertical channels 230 in a second horizontaldirection of the semiconductor device, as described above in connectionwith FIG. 1.

FIG. 6 is cross-sectional view of a vertical-channel memory device, inaccordance with another embodiment of the present invention,illustrating positioning of the cell region of the device on theperipheral circuit region of the device. Referring to FIG. 6, a cellstructure 334 is formed on a peripheral circuit region 302 of thedevice. In this embodiment, a plurality of peripheral circuittransistors 316 are provided on a substrate 300. A first interlayerdielectric (ILD) layer 318 is on the peripheral circuit transistors, andfirst interlayer contacts 320 connect the underlying transistors 316with conductive vias 322 formed on the first ILD 318. Similarly, secondand third ILD layers 324, 330, and corresponding second interlayercontacts 326, and second and third conductive vias 322, are provided toroute the signals between the cell structure 334 and the peripheralcircuit region 302.

A cell structure 334 including a single-crystal silicon substrate 332 ofthe type described above in connection with FIGS. 1, 2 and 3E-3P ispositioned on the third ILD layer 330 of the peripheral circuit region302. A fourth ILD 340 is provided on the resulting structure andinterlayer contacts 342 and conductive vias 344 route signals to andfrom the cell structure 334, including the word line signals and the bitline signals.

FIGS. 7A-7E are cross-sectional views of a method of forming thevertical-channel memory device of FIG. 6, in accordance with anotherembodiment of the present invention, illustrating the formation of thecell region of the device on the peripheral circuit region of thedevice.

Referring to FIG. 7A, a plurality of peripheral circuit transistors 316are provided on a substrate 300. The transistors include, for example, agate electrode 312, isolated from the substrate 300 by a gate oxidelayer 310, and source and drain regions in the substrate at sides of thegate electrode. A first interlayer dielectric (ILD) layer 318 is formedon the peripheral circuit transistors, and first interlayer contacts 320connect the underlying transistors 316 with conductive vias 322 form onthe first ILD 318.

Referring to FIG. 7B, second and third ILD layers 324, 330, andcorresponding second interlayer contacts 326, and second and thirdconductive vias 322, are formed on the resulting structure to route thesignals to and from the peripheral circuit region 302.

Referring to FIG. 7C, a single crystal silicon layer 332 is formed onthe resulting structure. The single-crystal silicon layer 332 provides afunction for the later formed cell region that is similar to thesubstrate 100 of FIGS. 1, 2 and 3A-3P.

Referring to FIG. 7D, a cell structure 334 is formed on the singlecrystal silicon layer 332, for example in the manner described above inconnection with FIGS. 1, 2 and 3A-3P.

Referring to FIG. 7E, the resulting structure is patterned in a cascadearrangement, to provide access to the word lines of the various celllayers as shown. A fourth ILD layer 340 is applied to the resultingstructure, as described above and interlayer contacts 342 and conductivevias 344 are patterned and formed to route signals to and from suitablenodes of the cell structure 334, including the word line signals and thebit line signals.

FIG. 8 is cross-sectional view of a vertical-channel memory device, inaccordance with another embodiment of the present invention,illustrating the positioning of the cell region of the device on theperipheral circuit region of the device. In this embodiment, a cellstructure 350 of the type described above in connection with FIGS. 4 and5A-5L is provided on the peripheral circuit region 302 of the device. Toaccomplish this, the processing steps shown in FIGS. 7A-7E may beperformed, using the cell structure of the type shown in FIGS. 4 and5A-5L.

Accordingly, in vertical-type semiconductor memory devices and methodsof forming the same, a single-crystal vertical channel can be employed,thereby reducing the likelihood of crystalline defects, and mitigatingthe number of resulting trap sites, leading to reduced deviceresistance, and therefore increased speed and decreased powerconsumption. Also, a charge trapping layer can be formed to surround thecontrol gate in the region of the vertical channel, leading to simplerand more reliable device formation. Further, the tunnel oxide positionedbetween the charge trapping layer and the vertical channel can be formedof a thermal oxide layer, which is more resistant to degradation overtime, leading to improved device reliability and endurance. This alsoprovides designers with greater flexibility in achieving desired devicecharacteristics.

FIG. 10 is a block diagram of a nonvolatile memory device in accordancewith exemplary embodiments of the present invention.

Referring to FIG. 10, a semiconductor memory device 400 may include acell array 410, a decoder 420, a page buffer 430, a bit line selectioncircuit 440, a data buffer 450 and a control unit 460. The semiconductormemory device 400 may comprise a vertical-type non-volatile flash memorydevice configured in accordance with the embodiments described herein.

The cell array 410 may include a plurality of memory blocks (not shown).Each memory block can include a plurality of pages (e.g., 32 pages, 64pages) and each page can include a plurality of memory cells (e.g.,512B, 2 KB) sharing one word line (WL). In one example, erase operationscan be performed on a memory block basis, and read and write operationscan be performed on a page basis.

The decoder 420 is connected to the cell array 410 by a plurality ofword lines WL and controlled by the control unit 460. The decoder 420receives an address (ADDR) from a memory controller (not shown) andgenerates a selection signal Yi so as to select a word line or a bitline. The page buffer 430 is connected to the cell array 410 by aplurality of bit lines BL.

The page buffer 430 stores data loaded from a buffer memory (not shown).The page buffer 430 loads page data and the loaded data issimultaneously programmed to a selection page when a program operationis performed. When a read operation is performed, the page buffer 430reads data from a selection page and temporarily stores the read data.Data stored in the page buffer 430 is transferred to the buffer memoryin response to a read enable signal.

The bit line selection circuit 440 responds to the selection signal Yiand selects a bit line (BL). The data buffer 450 is an input/outputbuffer used for transmitting data between a memory controller and theflash memory device 400. The control unit 460 receives a control signalfrom the memory controller and controls an internal operation of theflash memory device 400.

FIG. 11 is a block diagram of a system 500 including a semiconductormemory device in accordance with exemplary embodiments of the presentinvention. The system 500 may, for example, be employed in a wirelesscommunication device (e.g., PDA, a laptop computer, a portable computer,a web tablet, a wireless phone and a cell phone), or in an electronicdevice that can transmit and/or receive information in a wirelessenvironment.

The system 500 may include a controller 510, an input/output device 520such as a keypad, keyboard and a display, a memory 530, and a wirelessinterface 540. The controller 510 may include at least onemicroprocessor, digital signal processor, microcontroller or the like.The memory 530 may be used for storing an instruction code executed bythe controller 510 and used for storing user data. The memory 530 cancomprise a vertical-type nonvolatile memory device in accordance withsome exemplary embodiments of the present invention. The memory 530 canalso comprise various kinds of vertical-type memories, includingvertical-type random access volatile memory.

The system 500 may use a wireless interface 540 to transfer data to awireless communication network that communicates by RF signal or toreceive data from the wireless communication network that communicatesby RF signal. For example, the wireless interface 540 may include anantenna, a wireless transceiver and other wireless system elements.

The system 500 according to some exemplary embodiments of the presentinvention may be used in a communication protocol such as a thirdgeneration communication system (e.g., CDMA, GSM, NADC, E-TDMA, WCDMA orCDMA3000)

While embodiments of the invention have been particularly shown anddescribed with references to preferred embodiments thereof, it will beunderstood by those skilled in the art that various changes in form anddetails may be made herein without departing from the spirit and scopeof the invention as defined by the appended claims.

1. A semiconductor device, comprising: a plurality of interlayerdielectric layers on a substrate; a plurality of gate patterns, eachgate pattern between a neighboring lower interlayer dielectric layer anda neighboring upper interlayer dielectric layer; a vertical channelextending in a vertical direction through the plurality of interlayerdielectric layers and the plurality of gate patterns; a gate insulatinglayer between each gate pattern and the vertical channel that insulatesthe gate pattern from the vertical channel; and a blocking layer eachcorresponding gate patterns, the blocking layer comprising: a firstportion extending in the vertical direction between the gate pattern andthe gate insulating layer; a second portion extending in a horizontaldirection between the gate pattern and the neighboring upper interlayerdielectric layer; and a third portion extending in the horizontaldirection between the gate pattern and the neighboring lower interlayerdielectric layer.
 2. The semiconductor device of claim 1, wherein theblocking layer includes silicon oxide or other suitable high-k oxidelayer.
 3. The semiconductor device of claim 1, wherein the blockinglayer covers three sides of at least one of the plurality of gatepatterns.
 4. The semiconductor device of claim 1, further comprising acharge trapping layer positioned between each corresponding gateinsulating layer and blocking layer.
 5. The semiconductor device ofclaim 4, wherein the charge trapping layer includes ONO, nitride, orquantum-dot structures.
 6. The semiconductor device of claim 1, whereinthe gate insulating layer is disposed at the side wall of the verticalchannel.
 7. The semiconductor device of claim 1, wherein the gateinsulating layer includes a thermal oxide layer.
 8. The semiconductordevice of claim 1 wherein: an upper-most gate pattern of the pluralityof gate patterns comprises an upper select gate of an upper selecttransistor; a lower-most gate pattern of the plurality of gate patternscomprises a lower select gate of a lower select transistor; remaininggate patterns of the plurality of gate patterns between the upper selectgate and the lower select gate comprise control gates of memory celltransistors of a common string of the semiconductor device; controlgates of memory cell transistors sharing a same layer of the devicearranged in a first horizontal direction of the semiconductor device areconnected to provide word lines of the semiconductor device; memory celltransistors of a common string of the semiconductor device are coupledtogether in series by the vertical channel; upper portions of verticalchannels arranged in a second horizontal direction of the semiconductordevice are connected to provide bit lines of the semiconductor device;and the semiconductor device comprises a semiconductor memory device. 9.The semiconductor device of claim 1, wherein the interlayer dielectriclayer includes a silicon oxide layer.
 10. The semiconductor device ofclaim 1 wherein the plurality of interlayer dielectric layers eachcomprise a multiple-layered structure comprising a lower insulatinglayer, an intermediate insulating layer and an upper insulating layer,the lower and upper insulating layers comprising a material that hasetch selectivity relative to the intermediate insulating layer.
 11. Asemiconductor device, comprising: a plurality of interlayer dielectriclayers on the substrate; a plurality of gate patterns, each gate patternbetween a neighboring lower interlayer dielectric layer and aneighboring upper interlayer dielectric layer; a vertical channelextending in a vertical direction through the plurality of interlayerdielectric layers and the plurality of gate patterns; a gate insulatinglayer between each gate pattern and the vertical channel that insulatesthe gate pattern from the vertical channel; and a blocking layer eachcorresponding gate patterns and the vertical channel, wherein theblocking layer covers three sides of at least one of the gate pattern.12. The semiconductor device of claim 11, wherein the blocking layerincludes silicon oxide or other suitable high-k oxide layer.
 13. Thesemiconductor device of claim 11, wherein the blocking layer comprises:a first portion extending in the vertical direction between the gatepattern and the gate insulating layer; a second portion extending in ahorizontal direction between the gate pattern and the neighboring upperinterlayer dielectric layer; and a third portion extending in thehorizontal direction between the gate pattern and the neighboring lowerinterlayer dielectric layer.
 14. The semiconductor device of claim 11,further comprising a charge trapping layer between each correspondinggate insulating layer and blocking layer.
 15. The semiconductor deviceof claim 14, wherein the charge trapping layer includes ONO, nitride, orquantum-dot structures.
 16. The semiconductor device of claim 11,wherein the gate insulating layer is disposed at the side wall of thevertical channel.
 17. The semiconductor device of claim 11, wherein thegate insulating layer includes a thermal oxide layer.
 18. Thesemiconductor device of claim 11 wherein: an upper-most gate pattern ofthe plurality of gate patterns comprises an upper select gate of anupper select transistor; a lower-most gate pattern of the plurality ofgate patterns comprises a lower select gate of a lower selecttransistor; remaining gate patterns of the plurality of gate patternsbetween the upper select gate and the lower select gate comprise controlgates of memory cell transistors of a common string of the semiconductordevice; control gates of memory cell transistors sharing a same layer ofthe device arranged in a first horizontal direction of the semiconductordevice are connected to provide word lines of the semiconductor device;memory cell transistors of a common string of the semiconductor deviceare coupled together in series by the vertical channel; upper portionsof vertical channels arranged in a second horizontal direction of thesemiconductor device are connected to provide bit lines of thesemiconductor device; and the semiconductor device comprises asemiconductor memory device.
 19. The semiconductor device of claim 11,wherein the interlayer dielectric layer includes a silicon oxide layer.20. The semiconductor device of claim 11, wherein the plurality ofinterlayer dielectric layers each comprise a multiple-layered structurecomprising a lower insulating layer, an intermediate insulating layerand an upper insulating layer, the lower and upper insulating layerscomprising a material that has etch selectivity relative to theintermediate insulating layer.